A tracheostomy is a surgical procedure in which an opening is formed through the anterior surface of the neck into the trachea. The opening is referred to as a tracheostoma. A tracheostomy tube can be provided to extend between the tracheostoma and the trachea. A tracheostomy is performed for example when there is a malfunction, such as a result from injury or disorder, in respect of the nervous system or the respiratory passages, which malfunction results in an incapacity to obtain enough air. An inferior lung capacity or need of respiratory treatment may also result in a tracheostomy.
A laryngectomy is a surgical procedure, used for example to treat a carcinoma, which involves removal of the larynx or voice box and creation of a tracheostoma. A consequence of the procedure is that the trachea is no longer connected to the pharynx but is diverted to the tracheostoma. After this procedure, normal nasal function is not possible. In a subject whose breathing functions normally, the nose and the mucous membrane lining of the nasal cavity perform important functions in conditioning inhaled air. The convoluted passages and rich blood supply serve to increase both the temperature and humidity of the inhaled air to minimise the differential in these parameters with those of the surface of the lungs. Normally some heat and moisture is also captured from exhaled air prior to its release to the atmosphere. The mucous lining of the nasal passages also serves to remove particulate matter, such as fine dust particles, pollutants and microorganisms, from the inhaled air, and the action of cilia transports mucous and any particles away from the lungs.
When a patient has received a laryngectomy, in effect all inhaled air enters the lungs via the tracheostoma, and the nose is effectively not involved in the inhalation process. Exhaled air may pass through the tracheostoma or, if a voice prosthesis has been fitted, the stoma can be occluded so that the exhaled air is diverted through the voice prosthesis into the pharynx and the mouth, enabling the patient to speak. It is desirable that the flow of the exhaled air be controlled by means of a tracheostoma valve. In these situations, the valve can be arranged to remain open during breathing but, with a small additional increase in exhaled air flow, can be closed to divert the airflow.
In this respect filter devices and breathing protectors have been developed to enable moisturizing of inhaled air and removal of small particles and bacteriological substances in said inhaled air, to ensure minimized spreading of virus and bacteria. This has especially being an issue when the same respirator is used for multiple patients. This is to resemble the functions of a nose. However, there are several complications related to the design of such devices. Firstly, the user of such devices is in need of good moisturizing and filtering effect while keeping the size, such as the dead space area or volume, of the device as small as possible. Otherwise, the device will be unsuitable for children. Secondly, the moisturizing effect and filter effect is in need of large surface area, while not creating a too large resistance over the device. These criterions are contradictive, which the observant reader already has acknowledged. Also, a laryngectomy has to hold his finger or thumb over these devices when wishing to speak, to thereby obstruct the air flow through the device and the stoma through the tracheal wall, which will burden the filter with undue contamination, due to transfer of impurities from the finger of the user to the filter.
U.S. Pat. No. 5,848,590 discloses a filter assembly for filtering air that is to be breathed through a tracheostoma, comprising a housing and a filter component. The filter component is however movable within the housing, forcing the filter component and heat-moisture exchanger to be glued into one piece, forcing the additional manufacturing steps, making the manufacturing procedure complicated, time consuming, and thus costly. U.S. Pat. No. 5,666,950 discloses a similar filter component and device arrangement. Also, the filtering effect of these planar filters is very low.
WO 2008/132222 discloses a breathing protector for use in a stoma of a laryngectomized person. The breathing protector is provided with a heat-moisture exchanger, a bacteriological filter, and a closing mechanism. However, the proximal side is prone to contact the skin of the patient, and thus there is a risk for clogging and contaminating the filter. Also, because of the closing mechanism, the breathing protector of this kind has a large dead space, making the device large and increasing dead space, and hence not so usable for children. Also, a too large dead space results in a decrease in fresh air reaching the lungs of the patient. Furthermore, the arrangement of the different parts into the breathing protector necessitates gluing/welding, or other attachment means, making the manufacturing procedure complicated, time consuming, and thus costly.
Hence, it would be beneficial with a new breathing protector, allowing for a small, and space effective device, said device comprising a heat-moisture exchanging and bacterial/viral filtrating function with guarded filter surfaces, while simultaneously allowing for the possibility to omit specially designed filter bodies with unnecessary adhesion substances/elements there between. It would also be beneficial with arrangements and parts allowing for an easy assembling of such new breathing protectors.